The present invention relates to a unconventional displacement engine of the rotary type, and more particularly to a rotary engine having an improved force transfer mechanism, an improved rotor assembly with effective cooling, sealing and lubrications systems, and a multi-functional manifold.
In conventional internal combustion engines heat energy is converted to translating or reciprocal mechanical energy of pistons which is then converted to rotational energy that drives a drive shaft. Piston rings are provided as contact surfaces between the piston and cylinder walls. The rings seal the lower portion of a combustion chamber to retain compression, scrape excess oil from the cylinder walls and to transfer heat from the piston to the cylinder walls. Approximately 50% of all mechanical losses are attributed to the piston rings, and about one-half of these are attributed to oil scraping. Mechanical loss due to friction results in less heat being used for power generation.
In addition, the structural design of the conventional engine does not facilitate easy modification. For example, it is not possible to change engine displacement by changing sizes of engine components. Generally, a family of engines having different numbers of cylinders and different displacements are provided.
A currently commercially available rotary engine, such as the Wankel engine is compact, lightweight, simple in design and capable of producing high power relative to its size with high mechanical loss. However, the Wankel engine is not fuel efficient because of inherent problems due to the shape of the pistons, and poor heat transfer due to inadequate cooling of the rotating members.
A variety of rotary piston engines have been proposed recently to improve the Wankel engine by altering the piston shape and the mechanism that ensures proper movement of the pistons. One such engine is disclosed in U.S. Pat. No. 5,133,317 to Sakita which discloses a rotary engine having an eccentric elliptical gear assembly interconnected with the rotating piston assemblies. However, with this configuration, the teeth of the gear assembly may experience most of the internal forces generated during combustion and may fail. Further, the gear assembly is generally not compact, has many moving parts which contribute to mechanical loss, and may be expensive to manufacture and maintain.